ALEXANDER YO^ HUMBOUDT. 189 boldt, according to Ms own and Ms contemporaries' researches, does not consider as completed, "but as still continuing. As there are yet portions of the earth's surface which lie below the level of the ocean,—for instance, the Caspian Sea,* the Dead Sea7 the former 625, the latter 1230 feet below the level of the Medi- terranean,—so whole territories rise still, though per- haps scarcely perceptibly in the course of a human life. Thus the eastern shore of Scandinavia has risen 320 feet during 8000 years ; and Humboldt calculates that in 12,000 years, those portions of the sea near the shore, which are now covered by fifty fathoms of water, will be raised to the surface and become dry land. Thus tTae growth of the continent is proved! But if, on the one side, land is rising above the sea, one may also imagine a gradual sinking on the other; and Humboldt plainly foresees that some north-western portions of Europe, by the gradual depression of the surface, will sink below the water level and become sea. There is an absence of any proof for a real in- crease or decrease of the ocean, although in former ages the level of the sea was undoubtedly a widely different one to the present. Over the mountains and the plains, and over the unstable surface of tlie ocean, lies the earth-surround- ing sea of air, to which the oceanic waters refuse to Impart their warmth, as the refrigerated particles of water become heavier, and fall into the warmer depth. IBut as the air ocean has its wind currents, wMch re- turn according to regular laws (which Dowe especially has investigated), so there are also oceanic currents, which Humboldt has made the subject of interesting researches. Besides the well-known phenomena of ebb and tide, the movement of the waves in obedience to prevailing winds, and periodical air pressure, there * Humboldt remarks that the periodical, irregular rising and falling of the waters in the Caspian Sea, seems to be a proof that the soil is yet capable of making weak oscillations, even without earthquakes, which must have been more universal at the period when the earth's* crust was less thick.